Aqueous short-chain fluorine-containing acrylate polymers, methods of making and use thereof

Abstract

The application provides a water-based short-chain fluorine-containing acrylate polymer and a preparation method and application thereof, and relates to the material field.The water-based short-chain fluorine-containing acrylate polymer has a general structure as follows: the preparation method comprises the following steps: mixing a double-short-fluorine-chain monomer, a fluorine-containing alkyl acrylate monomer, an emulsifier, a co-emulsifier and deionized water, performing dispersion treatment, and then performing a copolymerization reaction in an oxygen-free environment by using an initiator, and quenching and purifying to obtain the water-based short-chain fluorine-containing acrylate polymer.The water-based short-chain fluorine-containing acrylate polymer is applied to a water-repellent and oil-repellent finishing agent for surface treatment of textiles, paper and rubber.The water-based short-chain fluorine-containing acrylate polymer provided by the application has excellent water-repellent and oil-repellent effects, avoids the problems of difficult degradation, biological accumulation and environmental hazards of long-chain fluorine-containing copolymers, is green and environment-friendly, and is friendly to the environment.

Description

Technical Field

[0001] This application relates to the field of materials, and more particularly to an aqueous short-chain fluorinated acrylate polymer, its preparation method, and its application. Background Technology

[0002] Fluorinated fabric finishing agents are based on perfluorinated or polyfluoroalkyl compounds (also known as fluorocarbon compounds). Perfluorinated or polyfluoroalkyl compounds are chemicals in which all or part of the hydrogen atoms in the carbon chain of the compound molecule are replaced by fluorine atoms to form a fluorocarbon chain structure. Because of the large number of CF bonds in the fluorinated chain segments and the extremely low surface tension of the -CF3 group, fluorinated fabric finishing agents can minimize the surface free energy and critical surface tension of the fabric, thus imparting excellent water and oil repellency, stain resistance, and washability. They are widely used in practical production and daily life, especially in the textile dyeing and finishing industry.

[0003] Fluorinated acrylate polymers are currently the main components of fluorinated water- and oil-repellent finishing agents on the market, but long-chain fluorinated acrylate polymers (-C...) n F 2n+1 During the oxidative degradation process, compounds with n≥8 (n ≥ 8) produce perfluorooctyl sulfonyl compounds (PFOS) and perfluorooctanoic acid compounds (PFOA). These compounds are bioaccumulative and capable of long-distance migration in the natural environment, are difficult to degrade, and have the potential to induce cell carcinogenesis, posing a potential threat to human health and the natural environment. Since 2006, Europe has imposed strict restrictions on the market entry and use of these products, and many countries have now completely banned the use of fluorinated polymers with a carbon chain length of 8C or higher. According to 3M, perfluorocarboxylic acids or sulfonates with a perfluoroalkyl carbon chain length ≤ 4 are not bioaccumulative. Furthermore, many studies have shown that fluorinated derivatives with a perfluorocarbon chain length ≤ 6 pose virtually no environmental harm. Because non-perfluoroalkyl groups (such as -C3F6H) are used as short fluorocarbon chains, the presence of some carbon-hydrogen bonds after surface treatment leads to a sharp increase in surface energy, making it difficult to achieve ideal water and oil repellency.

[0004] Therefore, the search and development of long-chain fluorinated acrylate polymers (-C) is crucial. n F 2n+1 Alternatives for (n≥8) have become a research hotspot in the textile and textile chemical manufacturing industries. Summary of the Invention

[0005] The purpose of this application is to provide an aqueous short-chain fluorinated acrylate polymer, its preparation method, and its application, in order to solve the above-mentioned problems.

[0006] To achieve the above objectives, this application adopts the following technical solution:

[0007] A water-based short-chain fluorinated acrylate polymer has the following general structural formula:

[0008]

[0009] Where Rf is -C m F 2m H, m = 1-6; X is -(CH2) n n = 1-6; a and b are independent positive integers from 1 to 100.

[0010] Optionally, a and b can each be 1, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 or any positive integer between 1 and 100.

[0011] This application also provides a method for preparing the aforementioned waterborne short-chain fluorinated acrylate polymer, comprising:

[0012] The di-short-chain fluorinated monomer, fluorinated alkyl acrylate monomer, emulsifier, co-emulsifier and deionized water are mixed, dispersed and then copolymerized in an anaerobic environment using an initiator. The copolymer is then quenched and purified to obtain the waterborne short-chain fluorinated acrylate polymer.

[0013] The structural formula of the dual short-fluorine chain monomer is:

[0014]

[0015] The structural formula of the fluorinated alkyl acrylate monomer is:

[0016]

[0017] Where Rf is -C m F 2m H, m = 1-6; X is -(CH2) n , n = 1-6.

[0018] Preferably, the emulsifier includes cationic surfactants and / or nonionic surfactants;

[0019] Preferably, the cationic surfactant comprises one or more of octadecyltrimethylammonium bromide (STAB), hexadecyltrimethylammonium bromide (CTAB), tetradecyltrimethylammonium bromide (TTAB), dodecyltrimethylammonium bromide (DTAB), dodecyltrimethylammonium chloride (DTAC), and cocoyl dihydroxyethyl polyether methylammonium chloride;

[0020] Preferably, the nonionic surfactant includes one or more of lauryl glucoside (APG1214), lauryl polyoxyethylene ether (AEO-9) type Brij L4, Brij L23, Brij 35 in the fatty alcohol polyoxyethylene ether series, as well as cocoyl glucoside and fatty alcohol polyoxypropylene ether.

[0021] The co-emulsifier includes one or more of the following: dodecyl mercaptan (SH), long-chain hydrocarbon hexadecane (HD), long-chain fatty alcohol hexadecyl alcohol (CA), n-butanol, ethylene glycol, ethanol, propylene glycol, and glycerol.

[0022] Preferably, the amount of the emulsifier is 3%-10% of the total mass of the di-short-chain fluorinated monomer and the fluorinated alkyl acrylate monomer;

[0023] Optionally, the amount of the emulsifier can be any value between 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10% or 3%-10% of the total mass of the di-short-chain fluorinated monomer and the fluorinated alkyl acrylate monomer;

[0024] Preferably, the mass ratio of the emulsifier to the co-emulsifier is (1-9):1;

[0025] Optionally, the mass ratio of the emulsifier to the co-emulsifier can be any value between 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or (1-9):1;

[0026] Preferably, the molar ratio of the bis-short-chain fluorinated monomer to the fluorinated alkyl acrylate monomer is (1-4):1.

[0027] Optionally, the molar ratio of the bis-short-chain fluorinated monomer to the fluorinated alkyl acrylate monomer can be any value between 1:1, 2:1, 3:1, 4:1 or (1-4):1.

[0028] Preferably, the mixing includes: dissolving the emulsifier and the co-emulsifier in deionized water to obtain an emulsified mixed solution, then mixing the bis-short-chain fluorinated monomer and the fluorinated alkyl acrylate monomer and transferring the mixture to the emulsified mixed solution, stirring and then homogenizing by high-speed stirring to obtain a monomer pre-emulsion.

[0029] Preferably, the amount of deionized water used is 50-75% of the total volume of the emulsified mixed solution;

[0030] Optionally, the amount of deionized water can be any value between 50%, 55%, 60%, 65%, 70%, 75% or 50-75% of the total volume of the emulsified mixed solution;

[0031] Preferably, the stirring is carried out at 30-50°C for 5-30 minutes;

[0032] Optionally, the stirring is carried out at any temperature between 30°C, 35°C, 40°C, 45°C, 50°C or 30-50°C, and the time can be any value between 5 min, 10 min, 15 min, 20 min, 25 min, 30 min or 5-30 min.

[0033] Preferably, the high-speed stirring homogenization process has a stirring rate of 5000-20000 r / min and a time of 10-30 min.

[0034] Optionally, the stirring rate of the high-speed stirring homogenization can be any value between 5000 r / min, 10000 r / min, 15000 r / min, 20000 r / min or 5000-20000 r / min, and the time can be any value between 10 min, 20 min, 30 min or 10-30 min.

[0035] Preferably, the copolymerization reaction is carried out at a temperature of 60-90°C;

[0036] Optionally, the temperature of the copolymerization reaction can be any value between 60°C, 70°C, 80°C, 90°C, or 60-90°C.

[0037] Preferably, the amount of the initiator is 0.5%-2% of the total mass of the di-short-fluorine chain monomer and the fluorinated alkyl acrylate monomer;

[0038] Optionally, the amount of the initiator can be any value between 0.5%, 1%, 1.5%, 2%, or 0.5%-2% of the total mass of the di-short-fluorinated monomer and the fluorinated alkyl acrylate monomer;

[0039] Preferably, the initiator is prepared in advance as a 5-10 g / L aqueous solution for use;

[0040] Optionally, the concentration of the initiator solution can be any value between 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L, 10 g / L, or 5-10 g / L;

[0041] Preferably, the initiator is added to the reaction system at a dropping rate of 10-30 s / drop;

[0042] Preferably, after the initiator is added, it is kept at 60-90°C for 5-20 hours.

[0043] Optionally, after the initiator is added, the temperature for heat preservation can be any value between 60℃, 70℃, 80℃, 90℃ or 60-90℃, and the time can be any value between 5h, 10h, 15h, 20h or 5-20h.

[0044] Preferably, the fluorinated acrylate monomers include one or more of the following: bis(2,2,3,3,4,4,5,5-octafluoropentoxy) acrylate, bis(2,2,3,3,4,4,5,5-octafluoropentoxy) methacrylate, bis(2,2,3,3,4,4,5,5-octafluoropentoxy) ethyl acrylate, 2,2,3,3,4,4,5,5-octafluoropentyl acrylate, 2,2,3,3,4,4,5,5-octafluoropentyl methacrylate, and 2,2,3,3,4,4,5,5-octafluoropentyl ethyl acrylate.

[0045] Preferably, the initiator comprises an azo compound and / or a persulfate compound;

[0046] Preferably, the azo compound includes one or more of azobisisobutylamidine hydrochloride, azobisisobutylimidazoline hydrochloride, azobisisobutylammonium valerate, and azobisisopropylimidazoline; the persulfate compound includes one or more of ammonium persulfate, potassium persulfate, and sodium persulfate.

[0047] This application also provides an application of the aforementioned water-based short-chain fluorinated acrylate polymer as a water- and oil-repellent finishing agent for surface treatment of textiles, paper, and rubber.

[0048] Preferably, the surface treatment method includes:

[0049] The aqueous short-chain fluorinated acrylate polymer is formulated into a finishing agent solution, and then the object to be treated is impregnated and rolled, followed by pre-drying, baking, first water washing, soap washing, second water washing, and drying.

[0050] Preferably, the concentration of the finishing agent solution is 10-100 g / L;

[0051] Optionally, the concentration of the finishing agent solution can be any value between 10 g / L, 20 g / L, 30 g / L, 40 g / L, 50 g / L, 60 g / L, 70 g / L, 80 g / L, 90 g / L, 100 g / L or 10-100 g / L.

[0052] Preferably, during the impregnation process, the impregnation time is 10-60 minutes;

[0053] Optionally, during the impregnation process, the impregnation time can be any value between 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, or 10-60 min;

[0054] Preferably, the immersion rolling is carried out using a 1-4 immersion 1-4 rolling method, with a roll residue rate of 70-90%;

[0055] Optionally, the rolling process can be any one of 1-dip 1-roll, 2-dip 2-roll, 3-dip 3-roll, 4-dip 4-roll, or 1-4-dip 1-4-roll, and the roll allowance can be any value between 70%, 75%, 80%, 85%, 90%, or 70% to 90%.

[0056] Preferably, the pre-baking temperature is 60-100℃ and the time is 1-5 minutes;

[0057] Optionally, the pre-baking temperature can be any value between 60℃, 70℃, 80℃, 90℃, 100℃ or 60-100℃, and the time can be any value between 1min, 2min, 3min, 4min, 5min or 1-5min.

[0058] Preferably, the baking temperature is 120-180℃ and the time is 1-5 minutes;

[0059] Optionally, the baking temperature can be any value between 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, 180℃ or 120-180℃, and the time can be any value between 1min, 2min, 3min, 4min, 5min or 1-5min.

[0060] Preferably, the concentration of the soaping agent used in the soaping is 2 g / L.

[0061] Compared with the prior art, the beneficial effects of this application include:

[0062] The waterborne short-chain fluorinated acrylate polymer (-C) provided in this application n F 2n+1 (n≤8), multiple short fluorocarbon chains are introduced onto the fluorinated acrylic monomer, replacing the long carbon chain fluorinated copolymer (-C n F 2n+1(n≥8), avoiding the problems of difficult degradation and bioaccumulation of long fluorocarbon chains, with minimal environmental impact, meeting environmental protection requirements, and improving the water and oil repellency of the finishing agent, while also overcoming the poor water and oil repellency of single short-chain fluoroacrylate polymers. The mechanism of action of the waterborne short-chain fluoroacrylate polymer provided in this application is as follows: among the bis-short-chain monomers and fluoroacrylate alkyl ester monomers, the bis-short-chain monomers are the main components, and the fluoroalkyl Rf is the main characteristic group of the polymer, which can significantly reduce the surface tension of the fiber and is the key part to provide water repellency. However, the water and oil repellency of a single short fluorocarbon chain is limited. To improve the water repellency of the finishing agent, multiple short fluorocarbon chains are introduced into component a as hydrophobic chains; generally, short-chain finishing agents have better water repellency but poorer oil repellency, so short-chain finishing agents are not widely used. Through structural design, another short-chain monomer component b is introduced to improve its oil repellency. Component b is a single fluorinated acrylate monomer, and the C=C in component b works synergistically with the bis-short fluorinated monomer during polymerization. X is a buffer unit; since the polarity of fluorocarbon chains is very strong, the intramolecular stability can be improved by adding a buffer unit to the polymer molecule.

[0063] The method for preparing waterborne short-chain fluorinated acrylate polymers provided in this application uses fine emulsion polymerization instead of solution polymerization and traditional emulsion polymerization to prepare short-chain fluorinated acrylate polymers. Deionized water is used as the solvent, the reaction conditions are mild, and the prepared emulsion is uniform and stable (the emulsion particle size distribution is below 200 nm, the particle size distribution region is compact and shows a single peak, there is no aggregation of large-diameter particles, and the emulsion distribution is uniform). The synthesis method is environmentally friendly and efficient, the product does not require post-treatment, the emulsion properties are stable, and the fabric properties are not affected after treatment.

[0064] The water-based short-chain fluorinated acrylate polymer provided in this application has good thermal stability of latex film, and the thermal decomposition initiation temperature can reach 230℃ and above. It can be widely used as a water- and oil-repellent finishing agent for surface treatment of textiles (such as cotton fabrics), paper, rubber, and polymer materials. Attached Figure Description

[0065] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.

[0066] Figure 1 The infrared spectrum of the polymer in Example 1;

[0067] Figure 2 XPS spectrum of polymer in Example 1;

[0068] Figure 3The thermogravimetric (TG-DTG) analysis spectrum of the polymer in Example 1;

[0069] Figure 4 The average particle size of the water- and oil-repellent emulsion of poly-short fluorinated acrylate in Example 1;

[0070] Figure 5 The infrared spectra of the cotton fabric before and after finishing in Example 1 are shown below.

[0071] Figure 6 XPS full spectrum of unfinished and finished cotton fabrics in Example 1;

[0072] Figure 7 SEM images of unfinished and finished cotton fabrics from Example 1;

[0073] Figure 8 This is a comparison of the water-repellent contact angles of untreated and treated cotton fabrics in Example 1.

[0074] Figure 9 The oil-repellent contact angle of the treated cotton fabric in Example 1;

[0075] Figure 10 The water-repellent and oil-repellent contact angles of the polymer-treated cotton fabric obtained in Comparative Example 1;

[0076] Figure 11 The water-repellent and oil-repellent contact angles of the polymer-treated cotton fabric obtained in Comparative Example 2;

[0077] Figure 12 This is a schematic diagram illustrating the effect of emulsifier dosage on the contact angle.

[0078] Figure 13 A schematic diagram showing the effect of the ratio of emulsifier to co-emulsifier on the contact angle;

[0079] Figure 14 The contact angle of the fabric obtained by finishing the polymer prepared with the compound emulsifier. Detailed Implementation

[0080] The implementation schemes of this application will be described in detail below with reference to specific embodiments. However, those skilled in the art will understand that the following embodiments are only for illustrating this application and should not be regarded as limiting the scope of this application. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0081] Example 1

[0082] This embodiment provides an aqueous short-chain fluorinated acrylate polymer, and the synthetic route is as follows:

[0083]

[0084] Its preparation method includes the following steps:

[0085] 1. Pre-emulsification

[0086] Weigh out monomers bis(2,2,3,3,4,4,5,5-octafluoropentoxy)acrylate (A1) (6 mmol 3.5823 g) and monomers 2,2,3,3,4,4,5,5-octafluoropentyl acrylate (B1) (3 mmol 0.8584 g) and mix them thoroughly. Weigh out 0.6217 g of hexadecyltrimethylammonium bromide (CTAB), 0.6217 g of lauryl alcohol polyoxyethylene ether (Brij L4), and 0.1382 g of dodecyl mercaptan (SH) (based on 1 / 9 of the emulsifier mass) and transfer them to a clean beaker. Add 10 mL of deionized water to the beaker to prepare an emulsifier aqueous solution. Add the monomer mixture to the emulsifier aqueous solution. Heat and stir the mixture in a 50°C water bath for 15 min. Homogenize the resulting mixture by high-speed stirring at 15000 r / min for 15 min using a high-speed shear dispersion emulsifier to prepare a monomer pre-emulsion.

[0087] 2. Fine emulsion polymerization

[0088] The monomer pre-emulsion prepared by pre-emulsification was transferred to a three-necked flask equipped with a thermometer, condenser, mechanical stirrer, and nitrogen protection. The mixture was slowly heated to the polymerization temperature of 65°C and held at this temperature for 30 minutes. Then, 0.1332 g of azobisisobutylamidine hydrochloride (AIBA) aqueous solution (1.5% of the monomer mass, 6 g / L) was slowly added dropwise over one hour until complete. After the addition was complete, polymerization was continued at 65°C for 12 hours. The reacted solution was cooled to room temperature and filtered. The resulting filtrate was an aqueous short-chain fluorinated acrylate polymer.

[0089] Characterization:

[0090] A suitable amount of filtered water-based short-chain fluorinated acrylate water- and oil-repellent finishing agent was taken, and the average particle size distribution of the emulsion was tested using a laser nanoparticle size analyzer. Then, a suitable amount of the filtered water-based short-chain fluorinated acrylate water- and oil-repellent finishing agent was uniformly coated onto a clean glass slide and dried in a vacuum drying oven at 100℃ until constant weight, obtaining a fine emulsion latex film. The fine emulsion latex film was analyzed using Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TG).

[0091] Depend on Figure 1 It can be seen that at 2940 and 2893cm -1 and 1450cm -1 The absorption peak at 1738 cm⁻¹ is a characteristic peak for methyl and methylene groups;-1 The absorption peaks at 1288 and 1226 cm⁻¹ are due to the stretching vibration of the C=O bond in the ester bond. Because the carbonyl group is highly polar, these peaks appear sharp in the spectrum. -1 The absorption peaks at 1162 and 1120 cm⁻¹ are characteristic peaks of the COC bond; -1 The absorption peak at 1680–1620 cm⁻¹ is due to the -CF₂- asymmetric vibration; the absorption peak at 1680–1620 cm⁻¹ is due to the -CF₂- asymmetric vibration. -1 The absence of characteristic peaks for C=C bonds suggests that the synthesized water-based short-chain fluorinated acrylate water- and oil-repellent finishing agent is likely a preliminary finding.

[0092] Depend on Figure 2 It can be determined from the peak positions that C1s, O1s, and F1s elements are present on the surface of the fluorinated acrylate polymer latex film, with chemical shifts around 284 eV, 532 eV, and 688 eV, respectively. The F element content on the latex film surface reaches 40.75%, indicating a relatively high content. This suggests that during film formation, the low surface energy fluorinated groups in the copolymer migrate to the film-air interface, resulting in a large accumulation of fluorine elements in the outermost layer of the copolymer film. The chemical shifts of C, O, and F differ depending on their linking groups. Peak separation and binding energy analysis reveal that C has five different chemical environments, while the two O groups in the ester group have somewhat different chemical environments, forming two peaks with similar shapes. The F group has a more similar chemical environment, thus exhibiting a single peak distribution.

[0093] Depend on Figure 3 It can be seen that before 231.3℃, the weight loss of the copolymer is relatively small, and this process mainly involves the evaporation of water and the decomposition of other small organic molecules in the system. Between 231.3℃ and 385.1℃, the side chains in the copolymer begin to decompose; as the temperature continues to increase, the decomposition intensifies. After 385.1℃, the main chain of the copolymer begins to decompose, reaching the maximum decomposition rate at 411.4℃. Between 431.2℃ and 600℃, the system weight slowly decreases, reaching a constant weight state, with a final weight loss of 97%–98%, indicating that the copolymer has essentially completed its decomposition at this temperature. In summary, polymer 1 demonstrates excellent high-temperature stability and good thermal properties, meeting the requirements for daily use.

[0094] Depend on Figure 4 It can be seen that the prepared fluorinated acrylate fine emulsion has a particle size C1 distribution below 200 nm, a peak value of 125 nm, a PDI of 0.25, a compact particle size distribution area, and a single peak state, without the aggregation of large particles, indicating that the prepared emulsion is uniformly distributed.

[0095] Fabric finishing:

[0096] A water-based short-chain fluorinated acrylate water- and oil-repellent finishing agent C1, obtained from fine emulsion polymerization, was formulated into a 60 g / L finishing agent solution. Cotton fabric was immersed in the finishing agent solution for 30 minutes using a two-dip, two-nip process with a nip-off rate of 80%. The fabric was pre-dried at 80°C for 3 minutes and then baked at 160°C for 3 minutes to obtain a pre-treated cotton fabric. After soaping and washing, the cotton fabric was dried in an oven at 100°C to obtain the finished fabric.

[0097] Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TG-DTG) were used to characterize and analyze the cotton fabrics before and after finishing.

[0098] Depend on Figure 5 It can be seen that new characteristic absorption peaks appeared on the surface of cotton fabrics treated with short-chain fluorinated acrylate water- and oil-repellent finishing agent C1, among which, 1738 cm⁻¹... -1 The peak at this point represents the stretching vibration of C=O in acrylate polymers, indicating that the short-chain fluorinated acrylate water- and oil-repellent finishing agent successfully reacted with cotton fabric.

[0099] Depend on Figure 6 It can be seen that the treated cotton fabric surface contains three elements: C, O, and F, with chemical shift peaks at 532 eV, 284.8 eV, and 688 eV, respectively. Compared with the original cotton fabric, the presence of F element is increased. This proves that the fluoropolymer has successfully reacted onto the cotton fiber surface.

[0100] Depend on Figure 7 As shown, A-1, A-1_007, and A-1_005 are untreated cotton fabrics magnified 200, 2000, and 20000 times, respectively; B-1, B-1_007, and B-1_005 are treated cotton fabrics magnified 200, 2000, and 20000 times, respectively. Comparing the surface morphology of the cotton fabrics before and after treatment reveals that the surface of the untreated cotton fabric fibers is relatively rough, with obvious wrinkles. The surface of the treated cotton fabric fibers becomes smooth and flat. This indicates that after treatment, the fluorinated copolymer forms a uniform hydrophobic film on the surface of the cotton fibers, encapsulating the fibers. The fluoroalkyl side chains of the short-chain fluorinated acrylate water- and oil-repellent finishing agent reduce the surface tension of the treated cotton fabric, resulting in good water-repellent properties.

[0101] The static contact angle of cotton fabrics before and after treatment with water-based short-chain fluorinated acrylate water-repellent and oil-repellent finishing agent C1 was measured using a C602 optical contact angle measuring instrument.

[0102] Depend on Figure 8 and Figure 9 It can be seen that the water contact angle of the treated cotton fabric can reach 154.7°, and the secondary oil contact angle can reach 115.2°.

[0103] Example 2

[0104] This embodiment provides an aqueous short-chain fluorinated acrylate polymer, and the synthetic route is as follows:

[0105]

[0106] Its preparation method includes the following steps:

[0107] 1. Pre-emulsification

[0108] Weigh out monomer A2 bis(2,2,3,3,4,4,5,5-octafluoropentoxy)methacrylate (6 mmol 3.6762 g) and monomer B1 2,2,3,3,4,4,5,5-octafluoropentyl acrylate (3 mmol 0.8584 g) and mix them thoroughly. Weigh out 0.2267 g tetradecyltrimethylammonium bromide (TTAB), 0.2267 g lauryl alcohol polyoxyethylene ether Brij L23, and 0.0647 g hexadecane (HD) (based on 1 / 7 of the emulsifier mass) and transfer them to a clean beaker. Add 10 mL of deionized water to the beaker to prepare an emulsifier aqueous solution. Add the monomer mixture to the emulsifier aqueous solution. Heat and stir the mixture in a 50°C water bath for 15 min. Homogenize the resulting mixture by high-speed stirring at 10000 r / min for 15 min using a high-speed shear dispersion emulsifier to prepare the monomer pre-emulsion.

[0109] 2. Fine emulsion polymerization

[0110] The monomer pre-emulsion prepared by pre-emulsification was transferred to a three-necked flask under nitrogen protection, equipped with a thermometer, condenser, and mechanical stirrer. The mixture was slowly heated to the polymerization temperature of 75°C and held at this temperature for 30 minutes. Then, 0.0906 g of azobisisobutyrazoline hydrochloride (AIBI) aqueous solution (2.0% of the monomer mass, 7 g / L) was slowly added dropwise over one hour until complete. After the addition was complete, polymerization was continued at 75°C for 15 hours. The reacted solution was cooled to room temperature and filtered. The resulting filtrate was the water-based short-chain fluorinated acrylate water- and oil-repellent finishing agent C2.

[0111] Example 3

[0112] This embodiment provides an aqueous short-chain fluorinated acrylate polymer, and the synthetic route is as follows:

[0113]

[0114] Its preparation method includes the following steps:

[0115] 1. Pre-emulsification

[0116] Weigh out monomer A3 bis(2,2,3,3,4,4,5,5-octafluoropentoxy)methacrylate (6 mmol 2.6772 g) and monomer B2 2,2,3,3,4,4,5,5-octafluoropentyl acrylate (3 mmol 0.7083 g), mix thoroughly, and weigh out 0.1016 g of octadecyltrimethylammonium bromide (STAB) and 0.1016 g of lauryl alcohol polyoxyethylene ether (Brij). 35. 0.0406 g of long-chain fatty alcohol cetyl alcohol (CA) (based on 1 / 5 of the emulsifier mass) was transferred to a clean beaker. 10 mL of deionized water was added to the beaker to prepare an emulsifier aqueous solution. The monomer mixed solution was added to the emulsifier aqueous solution. The mixed solution was heated and stirred in a 50 °C water bath for 15 min. The resulting mixed solution was homogenized by high-speed stirring at 5000 rpm for 15 min using a high-speed shear dispersion emulsifier to prepare monomer pre-emulsion C3.

[0117] 2. Fine emulsion polymerization

[0118] The monomer pre-emulsion prepared by pre-emulsification was transferred to a three-necked flask under nitrogen protection, equipped with a thermometer, condenser, and mechanical stirrer. The mixture was slowly heated to the polymerization temperature of 85°C and held at this temperature for 30 minutes. Then, 0.0338 g of azodicyanovalerate (ACVA) aqueous solution (1.0% of the monomer mass, 8 g / L) was slowly added dropwise over one hour until complete. After the addition was complete, polymerization was continued at 85°C for 17 hours. The reacted solution was cooled to room temperature and filtered. The resulting filtrate was the water-based short-chain fluorinated acrylate water- and oil-repellent finishing agent C3.

[0119] Example 4

[0120] This embodiment provides an aqueous short-chain fluorinated acrylate polymer, and the synthetic route is as follows:

[0121]

[0122] Its preparation method includes the following steps:

[0123] 1. Pre-emulsification

[0124] Weigh out monomers A4 bis(2,2,3,3,4,4-hexafluoropentoxy)methacrylate (6 mmol 2.7613 g) and B2 2,2,3,3,4,4-hexafluoropentylacrylate (3 mmol 0.7083 g), mix them thoroughly, weigh out 0.3122 g dodecyltrimethylammonium bromide (DTAB), 0.3122 g lauryl glucoside (APG1214), and glycerol (based on 1 / 3 of the emulsifier mass) and transfer them to a clean beaker. Add 10 mL of deionized water to the beaker to prepare an emulsifier aqueous solution. Add the monomer mixture to the emulsifier aqueous solution. Heat and stir the mixture in a 50 °C water bath for 15 min. Homogenize the resulting mixture by high-speed stirring at 20000 rpm for 15 min using a high-speed shear dispersion emulsifier to prepare the monomer pre-emulsion.

[0125] 2. Fine emulsion polymerization

[0126] The monomer pre-emulsion prepared by pre-emulsification was transferred to a three-necked flask under nitrogen protection, equipped with a thermometer, condenser, and mechanical stirrer. The mixture was slowly heated to the polymerization temperature of 95°C and held at this temperature for 30 minutes. Then, 0.0173 g of azobisisopropylimidazoline (AIP) aqueous solution (0.5% of the monomer mass, 9 g / L) was slowly added dropwise over one hour until complete. After the addition was finished, polymerization was continued at 95°C for 20 hours. The reacted solution was cooled to room temperature and filtered. The resulting filtrate was the water-based short-chain fluorinated acrylate water- and oil-repellent finishing agent C4.

[0127] Comparative Example 1

[0128] Using only a single fluorinated monomer for self-polymerization as a control, the reaction equation is as follows:

[0129]

[0130] The specific preparation method is as follows:

[0131] Weigh 0.1253 g of cetyltrimethylammonium bromide (CTAB), 0.1253 g of lauryl alcohol polyoxyethylene ether (Brij L4), and 0.0358 g of dodecyl mercaptan (NDM) and transfer them to a clean beaker. Add 10 mL of deionized water to the beaker to prepare an emulsifier aqueous solution. Weigh bis(2,2,3,3,4,4,5,5-octafluoropentoxy)acrylate (A1) (6 mmol 3.5823 g) and 0.0358 g of dodecyl mercaptan (NDM) (based on 1 / 7 of the emulsifier mass) and transfer them to a clean beaker. Heat and stir the mixture in a 50°C water bath for 15 min. Homogenize the resulting mixture by stirring at 15000 r / min using a high-speed shear dispersion emulsifier for 15 min to prepare a monomer pre-emulsion.

[0132] The monomer pre-emulsion prepared by pre-emulsification was transferred to a three-necked flask equipped with a thermometer, condenser, mechanical stirrer, and nitrogen protection. The mixture was slowly heated to the polymerization temperature of 65°C and held at this temperature for 30 minutes. Then, 0.0537 g of azobisisobutylamidine hydrochloride (AIBA) aqueous solution (1.5% of the monomer mass, 6 g / L) was slowly added dropwise over one hour until complete. After the addition was complete, polymerization was continued at 65°C for 12 hours. The reacted solution was cooled to room temperature and filtered. The resulting filtrate was the aqueous short-chain fluorinated acrylate polymer E1.

[0133] Depend on Figure 10 (C is the water contact angle, and D is the secondary oil contact angle) It can be seen that the water contact angle of the treated cotton fabric is 141.6° and the secondary oil contact angle is 88.5°.

[0134] This indicates that the water and oil repellency of the polymer obtained by polymerization of a single monomer is significantly lower than that of the polymer obtained in Example 1.

[0135] Comparative Example 2

[0136] Using copolymerization with fluorinated monomers and non-fluorinated monomers as a control, the reaction equation is as follows:

[0137]

[0138] Its preparation method is as follows:

[0139] Weigh out monomers bis(2,2,3,3,4,4,5,5-octafluoropentoxy)acrylate (A1) (6 mmol 3.5823 g) and butyl acrylate (C3) (6 mmol 0.7689 g) and mix them thoroughly. Weigh out 0.1523 g cetyltrimethylammonium bromide (CTAB), 0.1523 g lauryl alcohol polyoxyethylene ether (Brij L4), and 0.0435 g dodecyl mercaptan (NDM) (based on 1 / 7 of the emulsifier mass) and transfer them to a clean beaker. Add 10 mL of deionized water to the beaker to prepare an emulsifier aqueous solution. Add the monomer mixture to the emulsifier aqueous solution. Heat and stir the mixture in a 50°C water bath for 15 min. Homogenize the resulting mixture by high-speed stirring at 15000 r / min for 15 min using a high-speed shear dispersion emulsifier to prepare the monomer pre-emulsion.

[0140] The monomer pre-emulsion prepared by pre-emulsification was transferred to a three-necked flask equipped with a thermometer, condenser, mechanical stirrer, and nitrogen protection. The mixture was slowly heated to the polymerization temperature of 65°C and held at this temperature for 30 minutes. Then, 0.0652 g of azobisisobutylamidine hydrochloride (AIBA) aqueous solution (1.5% of the monomer mass, 6 g / L) was slowly added dropwise over one hour until complete. After the addition was complete, polymerization was continued at 65°C for 12 hours. The reacted solution was cooled to room temperature and filtered. The resulting filtrate was the aqueous short-chain fluorinated acrylate polymer F3.

[0141] Depend on Figure 11 (E is the water contact angle, and F is the secondary oil contact angle) It can be seen that the water contact angle of the treated cotton fabric can reach 133.4°, and the secondary oil contact angle can reach 78.2°.

[0142] To demonstrate the importance of emulsifiers and co-emulsifiers in this application, the following tests were conducted:

[0143] 1. Research on emulsifiers

[0144] Based on the reaction provided in Example 1, the effect of emulsifier dosage on the experiment was studied, as shown in Table 1 below:

[0145] Table 1. Data related to emulsifier dosage

[0146]

[0147] The fluorinated monomer A1:fluorinated monomer B1 ratio was 2:1 (mol:mol), the mass ratio of CTAB:Brij L4 was 1:1, the amount of co-emulsifier used was 1 / 7 of the total mass of emulsifier, the amount of initiator used was 1.5% of the total mass of monomers, the polymerization temperature was 65℃, and the polymerization time was 12h. The effect of the synthesized waterborne short-chain fluorinated acrylate polymer on the contact angle of cotton fabrics after finishing was investigated by changing the amount of compound emulsifier used to 4%, 5%, 6%, 7%, 8%, and 9% of the total mass of fluorinated monomers.

[0148] The results are as follows Figure 12As shown, with increasing emulsifier dosage, the dispersed monomer droplets become smaller and more numerous, resulting in a larger specific surface area, a higher probability of free radical capture, and a faster reaction rate. Due to the increased reaction sites, the monomers can polymerize more fully. The increased number and smaller particle size of monomer droplets in the system, along with the greater coverage of the emulsifier on the droplet surface, prevent small droplets from colliding and becoming larger, thus improving emulsion stability. However, excessive emulsifier dosage can lead to the formation of solubilizing micelles, increasing the likelihood of micelle nucleation in the system. This makes it impossible to fully guarantee that polymerization proceeds according to the principle of droplet nucleation, negatively impacting emulsion performance. Furthermore, excess emulsifier remaining in the final synthesized emulsion is difficult to remove, leading to emulsifier migration during fabric finishing, thereby reducing the water and oil repellency of the fabric. Therefore, the amount of emulsifier should be minimized while ensuring emulsion performance and the water and oil repellency of the fabric.

[0149] 2. Research on co-emulsifiers

[0150] Based on the reaction provided in Example 1, the effect of the amount of co-emulsifier on the experiment was studied, as shown in Table 2 below:

[0151] Table 2. Data related to the dosage of co-emulsifiers

[0152] Feeding Experimental Example 7 Experimental Example 8 Experimental Example 9 Implementation of test 10 Experimental Example 11 A1 3.5823g 3.5823g 3.5823g 3.5823g 3.5823g B2 0.8584g 0.8584g 0.8584g 0.8584g 0.8584g CTAB 0.1554g 0.1554g 0.1554g 0.1554g 0.1554g Brij L4 0.1554g 0.1554g 0.1554g 0.1554g 0.1554g NDM 0.3108g 0.1036g 0.0621g 0.0444g 0.0345g AIBA 0.0666g 0.0666g 0.0666g 0.0666g 0.0666g <![CDATA[H2O]]> 30mL 30mL 30mL 30mL 30mL

[0153] The results are as follows Figure 13 As shown. The difference between fine emulsion polymerization and traditional emulsion polymerization lies in the addition of a co-emulsifier. During pre-emulsification, an appropriate amount of co-emulsifier is added to the pre-emulsion system. Through high-speed shear dispersion of the emulsifier, larger fluorinated monomer droplets are homogeneously dispersed into smaller fluorinated monomer submicron droplets (50–500 nm in diameter). These submicron droplets are the primary reaction sites for fine emulsion polymerization. The polymerization reaction with the added co-emulsifier proceeds according to a predetermined reaction mechanism, promoting the adsorption of the emulsifier on the droplet surface. The co-emulsifier in the fine emulsion system does not act as a surfactant; instead, it inhibits or even eliminates the mass transfer process between monomer droplets through osmotic pressure, thereby suppressing the diffusion of monomers between droplets caused by the Ostwald ripening effect and maintaining the stability of the submicron monomers. The co-emulsifier used in fine emulsion polymerization must be insoluble in water but soluble in the monomer; long-chain alkanes or long-chain fatty alcohols are commonly used. The co-emulsifier can form an interfacial barrier on the monomer droplet surface, delaying the movement of monomers towards larger droplets. Adding a co-emulsifier can drastically reduce the interfacial tension between oil and water in the droplets, and can also reduce the size of the monomer droplets, forming stable submicron monomer droplets, and promoting the adsorption of emulsifiers on the droplet surface.

[0154] As the emulsifier:co-emulsifier ratio increases from 1:1 to 7:1, the contact angle of cotton fabric generally shows an upward trend, rising from an average contact angle of 144.1° to 151.1°. However, when the ratio increases from 7:1 to 9:1, the average contact angle of cotton fabric decreases to 150.0°. Therefore, both excessive and insufficient co-emulsifier usage will affect the preparation of water- and oil-repellent finishing agent emulsions containing short-chain fluorinated acrylates. Excessive co-emulsifier usage leads to its dispersion within or on the surface of monomer droplets, hindering the entry of free radicals, affecting the degree of polymerization of fluorinated monomers, and reducing the water- and oil-repellent effect of cotton fabrics. Conversely, insufficient co-emulsifier usage increases the probability of collisions between fluorinated monomer droplets, resulting in a severe Ostwald ripening effect between droplets. This leads to the generation of more agglomerates during polymerization due to the violent movement of monomer droplets, adversely affecting the stability of the emulsion.

[0155] 3. The type of compound emulsifier has an impact

[0156] The effect of compound emulsifiers on the experiment is shown in Table 3 below:

[0157] Table 3. Data related to the dosage of co-emulsifiers

[0158]

[0159] Note: The contact angles recorded in Table 3 are all water contact angles after the polymer-treated fabric is obtained.

[0160] The fabrics were treated with the polymers obtained in Experiments 12, 13, and 15, and the results are as follows: Figure 14 As shown (H is Experimental Example 12, I is Experimental Example 13, and G is Experimental Example 15). Based on the experimental results, the compounding scheme provided in Experimental Example 13 is the best.

[0161] The reason for this is that if ionic or nonionic emulsifiers are used alone, the resulting emulsion is prone to stratification and precipitation after prolonged storage. Therefore, ionic and nonionic emulsifiers are generally used in combination. This emulsification system improves the emulsification effect while maintaining the stability of the emulsion, achieving a synergistic effect. The alternating adsorption of ionic and nonionic emulsifier molecules on the surface of monomer droplets alleviates the electrostatic repulsion between like ions on the droplet surface, making it difficult for either type of emulsifier molecule to detach from the monomer droplet surface. Furthermore, the addition of nonionic emulsifiers reduces the charge density on the monomer droplet surface, making it easier for free radicals to enter the droplet interior, and increasing the polymerization rate without affecting the emulsion stability. Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0162] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the foregoing claims, any of the claimed embodiments can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

Claims

1. An aqueous short-chain fluorine-containing acrylate polymer, characterized by, The structural general formula is: ； wherein Rf is -C m F 2m H, m = 1-6; X is - (CH2) n , n = 1-6; a, b are each independently a positive integer from 1-100; The preparation method of the water-based short-chain fluorine-containing acrylate polymer comprises the following steps: The double short fluorine chain monomer, the fluorine-containing alkyl acrylate monomer, the emulsifier, the co-emulsifier and deionized water are mixed, and after dispersion treatment, the initiator is used for copolymerization reaction in an oxygen-free environment, and the water-based short-chain fluorine-containing acrylate polymer is obtained after quenching and purification. The structural formula of the double short fluorine chain monomer is: ； The structural formula of the fluorine-containing alkyl acrylate monomer is: ； The emulsifier comprises a cationic surfactant and / or a nonionic surfactant. The cationic surfactant comprises one or more of octadecyl trimethyl ammonium bromide, hexadecyl trimethyl ammonium bromide, tetradecyl trimethyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl trimethyl ammonium chloride, and cocoyl dihydroxyethyl polyether methyl ammonium chloride. The nonionic surfactant comprises one or more of Brij L4, Brij L23, Brij 35, and cocoyl glucoside in the lauryl alcohol polyoxyethylene ether series in the fatty alcohol polyoxyethylene ether series, and a fatty alcohol polyoxypropylene ether. The co-emulsifier comprises one or more of dodecanethiol, long-chain hydrocarbon hexadecane, long-chain fatty alcohol cetyl alcohol, n-butanol, ethylene glycol, ethanol, propylene glycol, and glycerol. The amount of the emulsifier is 3%-10% of the total mass of the double short fluorine chain monomer and the fluorine-containing alkyl acrylate monomer. The mass ratio of the emulsifier to the co-emulsifier is (1-9):

1. The molar ratio of the double short fluorine chain monomer to the fluorine-containing alkyl acrylate monomer is (1-4):

1. The mixing comprises: dissolving the emulsifier and the co-emulsifier in the deionized water to obtain an emulsified mixed solution, then mixing the double short fluorine chain monomer and the fluorine-containing alkyl acrylate monomer and transferring them into the emulsified mixed solution, stirring for 5-30 min at 30-50°C, and then performing high-speed stirring homogenization to obtain a monomer pre-emulsion. The amount of the deionized water is 50-75% of the total volume of the emulsified mixed solution. The stirring rate of the high-speed stirring homogenization is 5000-20000 r / min, and the time is 10-30 min. The temperature of the copolymerization reaction is 60-90°C.

2. The aqueous short-chain fluoroacrylate polymer according to claim 1, characterized in that, The amount of the initiator is 0.5%-2% of the total mass of the double short fluorine chain monomer and the fluorine-containing alkyl acrylate monomer.

3. The aqueous short-chain fluoroacrylate polymer according to claim 1, characterized in that, The initiator is prepared into a 5-10 g / L aqueous solution in advance for use.

4. The aqueous short-chain fluoroacrylate polymer of claim 1, wherein, The initiator is added to the reaction system at a dropping rate of 10-30 s / drop.

5. The aqueous short-chain fluoroacrylate polymer of claim 1, wherein, After the addition of the initiator is completed, the reaction system is incubated at 60-90°C for 5-20 h.

6. The aqueous short-chain fluoroacrylate polymer according to any one of claims 1 to 5, characterized in that, The initiator comprises an azo compound and / or a persulfate compound. The azo compound comprises one or more of azobisdimethylamid acid hydrochloride, azobisdimethylimidazole hydrochloride, azobis cyanovaleric acid, and azobisdiisopropylimidazole; and the persulfate compound comprises one or more of ammonium persulfate, potassium persulfate, and sodium persulfate.

7. The aqueous short-chain fluoroacrylate polymer of claim 1, wherein, The fluorine-containing alkyl acrylate monomer comprises 2,2,3,3,4,4,5,5-octafluoropentyl acrylate.

8. Use of the aqueous short-chain fluorine-containing acrylate polymer according to claim 1, characterized in that Water and oil repellent finishing agent for surface treatment of textiles, paper and rubber.

9. Use according to claim 8, characterized in that, The method for surface treatment comprises: The water-based short-chain fluorine-containing acrylate polymer is prepared into a finishing agent solution, then the treatment object is padded, and then pre-drying, baking, first water washing, soaping, second water washing and drying are carried out.

10. Use according to claim 9, characterized in that, The concentration of the finishing agent solution is 10-100 g / L.

11. Use according to claim 9, characterized in that, The dipping time is 10-60 min.

12. The use according to claim 9, characterized in that, The padding is carried out in 1-4 dipping and 1-4 padding mode, and the padding rate is 70-90 %.

13. The use according to claim 9, characterized in that, The pre-drying temperature is 60-100 ℃, and the time is 1-5 min.

14. The use according to claim 9, characterized in that, The baking temperature is 120-180 ℃, and the time is 1-5 min.

15. The use according to claim 9, characterized in that, The concentration of the soaping agent used in the soaping is 2 g / L.

Images